1. Field of the Invention
The present invention relates to circuit board connectors for connecting two circuit boards together.
2. Description of the Related Art
There are two types of circuit board connectors for connecting two circuit boards each other; one type is a socket housing type that can be dismantled even after product assembling and the other is a type that is fixed by soldering during product assembling. Among the latter type, which is fixed by soldering, the one as described below is known. This circuit board connector comprises, as illustrated in FIG. 13, a main body portion 2, a first connecting portion 1 for connection to a first circuit board, a second connecting portion 4 for connection to a second circuit board, and a lead portion 3 located between the second connecting portion 4 and the main body portion 2. The main body portion 2 comprises an auxiliary connecting portion 21 formed from a portion of the main body portion 2, so that the connecting strength is improved by making connection with the first circuit board at two points, at the first connecting portion 1 and the auxiliary connecting portion 21.
As illustrated in FIG. 14, when connected to a circuit board of an electronic apparatus such as a VTR, an electronic device 7 such as a tuner is arranged uprightly in order to reduce the mounting area of the circuit board. This necessitates the second connecting portion 4 to be drawn out from a narrow surface of the circuit board that is arranged, in the electronic device, parallel to a wide surface in the electronic apparatus, and therefore, the first connecting portion 1 and the auxiliary connecting portion 21 are bent when connected to a circuit board within the electronic device.
The outer shape of the above-described circuit board connector is, as illustrated in FIG. 15, formed by press cutting a single sheet of conductive plate material 5 the front and back sides of which have plating layers 6 of tin, nickel, or the like that have been formed thereon in advance. Thus, the transverse cross sections of the first connecting portion 1, the second connecting portion 4, and the auxiliary connecting portion 21 are formed to be rectangular.
However, cut surfaces 11 created by the press cutting are not provided with the plating layers and therefore have lower solder wettability than those in which a plating layer is formed on the entire surfaces. Moreover, there is a certain length of time until an electronic device equipped with the circuit board connector is shipped to the user and mounted onto a circuit board of an electronic apparatus. During that time, the second connecting portion of the circuit board connector is oxidized or rusted, and consequently a problem arises that solder wettability reduces.
In order to solve the foregoing problem, a method has been proposed in which re-plating is carried out for the circuit board connector after the press-cutting so that a plating layer is formed on the entire surface.
Re-plating the terminal, however, adds an extra manufacturing step and also increases cost. Moreover, the re-plating process usually adopts a barrel plating method, which involves putting samples to be plated into a barrel-shaped container containing a plating solution and revolving the barrel-shaped container, and in the course of this process, the terminals deform or get tangled, reducing the yield and leading to a further increase in cost. Furthermore, if a thin conductive plate material is used for cost reduction, the mechanical strength of the circuit board connector degrades, resulting in breakage during the manufacturing process and the mounting process to a circuit board, which also reduces the manufacturing yield.
The present invention has been accomplished to solve such problems, and it provides a circuit board connector with which good soldering is possible even without performing a re-plating process.